No refuge for bees in field margins where “chemical cocktails” lurk, say researchers

Field margins are the outer edges of fields that lie between the crop and the field boundary, they are not merely a wasted edge left wild; in fact, they provide a vital habitat for some of our much-loved species, from grasses and wildflowers, to the birds and insects that feast on their seeds and nectar.

These areas are doubly important where none pollinated mono crops grow, these vast areas of crops do not need #pollination, are pollinator deserts and produce no pollen or nectar. There would be little to no benefit for any pollinator if it were not for the field margins.

Where field edges are less productive, some farmers deliberately leave arable field margins. They take many forms including uncropped #wildlife strips; ‘conservation headlands’ which form the outer edge of the crop, the thinking was that these areas did not get so many #pesticides, until now.

Wildflowers in field margins can contain a mix of crop protection chemicals in their pollen which is likely to have complex effects on visiting #bees, according to research at Sussex University supported by the Soil Association.

To combat #bee decline, the Government’s Pollinator Strategy includes creating safe havens for bees by increasing flower habitats next to fields, but the research claims these can be rich in toxic chemicals.Hawthorn pollen represents a major share of the total pollen collected by both honeybees and bumble bees, but the pollen from hawthorn collected by honeybees in particular was found to be contaminated by up to six pesticides, at concentrations up to 29 ng/g for the fungicide carbendazim.Professor Dave Goulson, one of the authors of the paper, said: “Insects visiting wildflowers in field margins are chronically exposed to a cocktail of chemicals. The effects that this has on their health have never been studied, and there is an urgent need to do so. In the meantime, the precautionary principle would suggest that we should take steps to reduce this exposure as much as possible.”The study, published in Environment International, did not examine bees’ exposure via nectar, which researchers intend to address in future, while understanding the effects of bees’ simultaneous exposure to multiple pesticides in the field remains “a major challenge”, the researchers said.